Archive for February, 2012

Feb201228

If you think about it, you probably feel as though you have both good and bad memory days- maybe even hours. I like to think that my memory is pretty strong as a general rule, but there are periods of time where I’m just drawing blanks. There’s a whole host of reasons for these variations. After all, it’s not as though every person is born with a “memory score” that permenantly determines their ability to recall information. Like everything related to our minds, it’s far more intricate than that.

New findings from a prestigious center of neuroscience are demonstrating the significant relationship between levels of theta brain wave activity and our ability to remember at that moment in time. A paper describing this work, from scientists at UC Davis, was recently published in the journal Proceedings of the National Academy of Sciences.

To prove their case, professors and graduate students measured theta wave oscillations in the brains of volunteers during a memory test. Volunteers were asked to memorize a series of words. They later had to recall whether they had seen the word previously, and the context in which the word was seen. Volunteers who were experiencing higher levels of theta wave activity right before they were asked to remember an item were more likely to remember correctly.

Memory recall improved only when volunteers had high theta activity before they heard the cues. If it had been the case that theta activity had increased only after the cues were given, this study would instead suggest that theta waves were stimulated by the cues themselves—perhaps an indicator that the brain was processing a new challenge. But that was not the outcome here. Subjects whose brains were in a high-theta state were essentially “primed” to do better on the memory test once it started.

Of course, this should not be taken to mean that high levels of theta activity are the only factor behind successful memory recollection, but the study does lend support to the idea that everyday memory ability is just as much as a reflection of what’s going on inside the mind as the context outside of it.

“The work goes against the assumption that the brain is waiting to react to the external world. In fact, most of the brain is busy with internal activity that is not related to the outside world — and when external stimuli come in, they interact with these spontaneous patterns of activity.”

– Charan Ranganath, Professor, UC Davis Center for Neuroscience

In this study, the researchers did not actually attempt to stimulate theta activity- they were merely measuring it and recording results. Their hope is that research could lead to treatments for memory loss. Ideally, audio visual stimulation methods to increase theta activity will be part of the dialogue as this research moves forward.